Can Wellbutrin and Zoloft Cause Hand Tremors?
Yes, both bupropion (Wellbutrin) and sertraline (Zoloft) can cause hand tremors, and this risk increases when they are used together. Tremor is a recognized adverse effect of both medications individually, and combining them may compound this risk through their distinct but complementary effects on neurotransmitter systems.
Evidence for Sertraline (Zoloft) and Tremor
Sertraline is explicitly listed as causing tremors as a typical side effect of SSRIs. 1
- The American Family Physician guidelines specifically state that SSRIs, including sertraline, commonly cause "sweating, tremors, nervousness, insomnia or somnolence, dizziness, and various gastrointestinal and sexual disturbances" 1
- In overdose situations with sertraline, tremor is among the most common signs and symptoms, along with agitation, tachycardia, and nausea 2
- SSRIs are well-recognized tremorogenic drugs in clinical practice 3
- Tremor can occur at therapeutic doses and does not require toxic levels 4
Evidence for Bupropion (Wellbutrin) and Tremor
Bupropion explicitly lists tremor as a common adverse effect occurring in at least 5% of patients at a rate twice that of placebo. 1, 5
- At 300 mg/day of bupropion sustained-release, tremor is specifically identified as occurring in at least 5% of patients at twice the placebo rate 5
- The FDA label for bupropion lists tremor among common adverse effects, along with agitation, dry mouth, insomnia, headaches, nausea, and constipation 6
- Bupropion's mechanism involves norepinephrine and dopamine reuptake inhibition without serotonin activity, which can contribute to tremor through increased adrenergic tone 6
Risk When Combining Both Medications
When bupropion and sertraline are used together, the tremor risk may be additive or synergistic.
- While there are no specific studies on the combination's effect on tremor rates, both medications independently cause tremors through different neurotransmitter mechanisms 1, 6
- The combination affects multiple neurotransmitter systems (serotonin via sertraline, norepinephrine and dopamine via bupropion), which may increase the likelihood of tremor 6, 3
- Drug-induced tremors from psychiatric medications are common and typically dose-related 3, 4
Clinical Management Approach
If tremor develops on this combination, consider the following steps:
- Assess severity and functional impact: Determine if the tremor interferes with activities of daily living, writing, eating, or occupational tasks 3
- Review dosing: Both medications may cause more tremor at higher doses; consider if dose reduction is feasible while maintaining therapeutic benefit 1, 5
- Timing considerations: Tremor typically appears within days to weeks of starting or increasing doses 3, 4
- Rule out other causes: Exclude caffeine excess, thyroid dysfunction, essential tremor, or other medications that may contribute 3
- Consider medication adjustment: If tremor is disabling, switching one agent to an alternative with lower tremor risk (such as mirtazapine instead of sertraline) may be warranted 1
Important Caveats
Do not confuse medication-induced tremor with serotonin syndrome, which is a medical emergency. 7
- Serotonin syndrome includes tremor but also presents with mental status changes, muscle rigidity, clonus, hyperreflexia, autonomic instability (hypertension, tachycardia, diaphoresis), and hyperthermia 7
- Simple tremor without these additional features is likely a benign side effect rather than serotonin syndrome 7, 3
- If serotonin syndrome is suspected, discontinue all serotonergic agents immediately and seek emergency care 7
Tremor from these medications is usually benign and may improve with time or dose adjustment, but it warrants clinical attention if functionally disabling. 3, 4